The invention generally relates to air bag systems and more particularly to a side impact or rollover air bag system located in an outboard portion of a vehicle seat.
The prior art is replete with air bag systems to protect one or more occupants in a side impact and/or rollover event. These systems require that the air bag be mounted in or on a door adjacent to a vehicle seat, or on the vehicle seat. FIG. 1 schematically illustrates an air bag safety system 20 mounted in an outboard portion 22 of a vehicle seat 24 adjacent a side of the vehicle. The system 20 comprises an inflator 26 and an expandable air bag 28. Upon activation of the inflator, inflation gasses are produced causing the air bag 28 to tear open a seam 29 in the seat or open a movable door (not shown), also in the seat. Upon inflation, the air bag is positioned between an occupant, generally shown by phantom line 30, and the side 32 of the vehicle. As illustrated in FIG. 1, the air bag 28 is relatively small and is designed to protect the torso area of an adult. Air bags may also include an upper appendage or second chamber generally shown by phantom line 28', which is illustrative of a head chamber of a larger air bag.
As can be seen from FIG. 1, the occupant 30 is shown relatively small and the head 36 of the occupant is positioned adjacent the torso portion or lower chamber of the air bag. This orientation is illustrative of one of the out-of-position (OOP) seating conditions of the occupant that might exist in a vehicle. As an example, the occupant 30 can be thought of as a small child, having his or her head cradled in the void between the outward side portion 22 of the seat and the vehicle side 32. Upon inflation of the air bag 28, the occupant's head 36 or other portions of the occupant's body may be unfavorably interfered with by the inflating air bag 28.
Reference is made to FIGS. 2A and 2B which diagrammatically illustrate two air bags 28 and 28'. Air bag 28 is typically manufactured utilizing two generally identical panels of woven material which are sewn about a peripheral edge shown as 40. The air bag includes means, such as an opening, for receiving the inflator 26 therein. FIG. 2B illustrates the enlarged air bag 28' having a lower or torso chamber 28a and an upper or head chamber 28b. These chambers are separated by a separator panel or line of stitches generally shown as 42 which includes a plurality of vent openings 44 to allow the migration of the inflation gas from the lower chamber to the upper chamber.
Consider the operation of the air bags shown in FIGS. 2A and 2B in conjunction with the construction of the vehicle shown in FIG. 1. As is known, the crush zone between the side of the vehicle 32 and the occupant 30 is relatively small in relationship to a side impact collision. Consequently, to protect the occupant from injury during this type of event, the inflator must relatively quickly (within 8-10 milliseconds) inflate the air bag and cause same to be repositioned between the occupant and the vehicle side. To achieve the repositioning of the air bag in the required timeframe requires that the inflator be rather aggressive, that is, it is capable of producing a significant amount of inflation gas within a few milliseconds. As the inflator 26 produces the gasses, experience has shown that air bags constructed similar to those shown in FIGS. 2A and 2B push the forward edge 46 of the torso chamber outwardly extremely quickly. Of course, prior to being inflated the air bag 28 is maintained in a compact folded orientation within a pocket located within the upholstered side or side wing of the vehicle seat. If the occupant 30 is in an out-of-position orientation, this type of deployment of the air bag may induce certain occupant injuries.
It is an object of the present invention to provide an air bag which controls the pressure gradients generated within the torso or lower chamber of the air bag to lessen out-of-position-induced occupant injury. Accordingly the invention comprises: An air bag system for side impact protection comprising: an air bag (50) having an inflatable first chamber (50a) formed of two joined-together first: (52a) and second (52b) panels of material, the first chamber including a forward part (26) and an opposite rear part (60); an inflator (26) for generating inflation gas to inflate the air bag, the inflator including exit ports (26a) which channel the inflation gas into the first chamber in a determinable direction; the air bag further including a flow diverter (70, 90) positioned to receive inflation gas and to divert at least a component of the inflation gas to flow generally perpendicular to the first direction. In one embodiment the flow diverter is formed as an open-topped tube; in another embodiment the flow diverter includes a plurality of vent openings in the side of the tube. In a third embodiment of the invention the diverter is formed by a permeable sack of material. In another embodiment of the invention the rear of each of the first and second panels includes a curved portion which is separated by a curved separator panel to form a pressure accumulator.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.